Improvement in low-water alarms for steam-boilers



J, R. BROWN 8:. W. A. FOSKETT.

Law Water Alarms fur Steam-Boiiers.

Patented Feb. 4,1873.

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7 linemen? java/2 707 UNITED STATES,

PATENT OFFICE;

JOSEPH R. BROWN AND \VILLIAM A. FOSKETT, OF NEW HAVEN, UONN.

IMPROVEMENT IN LOW-WATER ALARMS FOR STEAM-BOILERS.

Specification forming part of Letters Patent No. 135,519, dated February4, 1873.

To all whom it may concern: 7 Be it known that we, JOSEPH R. BROWN and.WILLIAM A. FosKETT, both of New Haven, in the county of New Haven andState of Connecticut, have invented a new Improvement in Low-WaterDetector; and we do hereby declare the following, when taken inconnection with the accompanying drawing and the letters of referencemarked thereon, to he afull, clear, and exact description of the same,and which said drawing constitutes part of this specification, andrepresents, in-

Figure 1, a frontview Fig.2, avertical central section of the device asapplied to a steamboiler.

lhis invention relates to a device to indicate by an alarm when thewater in the boiler has fallen below a certain defined point, theobjectbeing to employ a fusible plug, by the melting of which the alarmwill be opened, and this plug arranged in a position independent of thewater-communicatin g tube, and

so that the steam which sounds the alarm will be taken from above thewatermark independent of the water-tube.

A is a shell of any desirable form, through which extends a hollow bar,B, and from this hollow bar an opening, 0, communicates directly to awhistle, D, or other alarm device. Into the chamber E within the shell Aa'tube, F, is arranged, communicating with the boiler below thewater-line, here represented as at- G. Into the hollow bar B, fromeither end, a tubular screw, H H, is inserted, and between the two thefusible material a is placed and held in that position by the saidscrews. From one of the screws H a tube, L, leads to the boiler abovethe water-mark, but is bent so that the water will stand in the bend,preventing the steam from coming in contact with the fusible materiala,- and this bend being outside the boiler the water in the bend will becool, or so low a temperature as not to affect the fusible material. ThechamberE will also be filled with water so long as the water remainsabove the tube F, but so soon as the water falls below the tube F thenthe water in the chamber and tube Fwill flow back into the boiler and bereplaced by hot steam, which will quickly heat the bar 13 to thetemperature required to fuse the material a. So soon as this fusiontakes place the steam driving through the tube L'will force the fusedmetal into and through the tube H, leaving a communication direct fromthe boiler to the whistle, so that steam only can reach the whistle; Thewater which may have been in the tube L, and is there by condensation,will quickly pass out.

In most of the devices of this class the communication with the whistleis made directly with the water-communicating tube; hence more or lesswaterwill be thrown from the Whistle when the alarm is sounded, makingitdifiicult to approach the boiler for the rearrangement of the fusiblematerial but as steam only by this device can reach the whistle thisdifliculty is-overcome.

It is not positively essential that the plug or screw H should betubular; but practically we find it convenient to make it so.

Ve claim asour invention- In combinationwith the .chamber E having thehollow tube B arranged therein, and a passage, 0, communicating to thealarm, the water-tube F, steam-tube L, and the fusible ma terial a, thesaid fusible material arranged in the hollow tube B, sov as to close thesteam tube L, substantially in the manner described, and for the purposespecified.

JOSEPH R. BROWN. \VM. A. .FOSKETT.

Witnesses:

A. J. TIBBITS, J. H. SHUMWAY.

